Regime forces massed Saturday in northwest Syria, a monitor said, in an apparent bid to press an offensive against jihadists and allied rebels that has heightened tensions with neighbouring Turkey.After eight years of civil war, the jihadist-run region of Idlib on the Turkish border is one of the last to escape the Damascus government's control.

Backed by Russia, Syrian President Bashar al-Assad's forces have chipped away at the south of the stronghold in recent weeks after months of deadly bombardment.